Hassanzadeh Sajad, Jalessi Maryam, Jameie Seyed Behnamedin, Khanmohammadi Mehdi, Bagher Zohre, Namjoo Zeinab, Davachi Seyed Mohammad
Skull Base Research Center, Hazrat Rasoul Hospital, The Five Senses Health Institute, Iran University of Medical Sciences, Tehran, Iran.
Neuroscience Research Center (NRC), Iran University of Medical Sciences, Tehran, Iran.
Biochem Biophys Rep. 2021 Jan 25;25:100905. doi: 10.1016/j.bbrep.2020.100905. eCollection 2021 Mar.
Functional improvement after spinal cord injury remains an unsolved difficulty. Glial scars, a major component of SCI lesions, are very effective in improving the rate of this recovery. Such scars are a result of complex interaction mechanisms involving three major cells, namely, astrocytes, oligodendrocytes, and microglia. In recent years, scientists have identified two subtypes of reactive astrocytes, namely, A1 astrocytes that induce the rapid death of neurons and oligodendrocytes, and A2 astrocytes that promote neuronal survival. Moreover, recent studies have suggested that the macrophage polarization state is more of a continuum between M1 and M2 macrophages. M1 macrophages that encourage the inflammation process kill their surrounding cells and inhibit cellular proliferation. In contrast, M2 macrophages promote cell proliferation, tissue growth, and regeneration. Furthermore, the ability of oligodendrocyte precursor cells to differentiate into adult oligodendrocytes or even neurons has been reviewed. Here, we first scrutinize recent findings on glial cell subtypes and their beneficial or detrimental effects after spinal cord injury. Second, we discuss how we may be able to help the functional recovery process after injury.
脊髓损伤后的功能改善仍然是一个未解决的难题。胶质瘢痕是脊髓损伤病变的主要组成部分，对提高这种恢复率非常有效。这种瘢痕是由涉及三种主要细胞（即星形胶质细胞、少突胶质细胞和小胶质细胞）的复杂相互作用机制产生的。近年来，科学家们已经确定了反应性星形胶质细胞的两种亚型，即诱导神经元和少突胶质细胞快速死亡的A1星形胶质细胞，以及促进神经元存活的A2星形胶质细胞。此外，最近的研究表明，巨噬细胞极化状态更多地是M1和M2巨噬细胞之间的一种连续状态。促进炎症过程的M1巨噬细胞会杀死其周围的细胞并抑制细胞增殖。相比之下，M2巨噬细胞促进细胞增殖、组织生长和再生。此外，少突胶质前体细胞分化为成熟少突胶质细胞甚至神经元的能力也已得到综述。在这里，我们首先仔细研究关于胶质细胞亚型及其在脊髓损伤后有益或有害影响的最新发现。其次，我们讨论如何能够帮助损伤后的功能恢复过程。
